The patch titled
Subject: zram: fix broken page writeback
has been added to the -mm tree. Its filename is
zram-fix-broken-page-writeback.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/zram-fix-broken-page-writeback.pa…
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/zram-fix-broken-page-writeback.pa…
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Minchan Kim <minchan(a)kernel.org>
Subject: zram: fix broken page writeback
commit 0d8359620d9b ("zram: support page writeback") introduced two
problems. It overwrites writeback_store's return value as kstrtol's
return value, which makes return value zero so user could see zero as
return value of write syscall even though it wrote data successfully.
It also breaks index value in the loop in that it doesn't increase the
index any longer. It means it can write only first starting block index
so user couldn't write all idle pages in the zram so lose memory saving
chance.
This patch fixes those issues.
Link: https://lkml.kernel.org/r/20210312173949.2197662-2-minchan@kernel.org
Fixes: 0d8359620d9b("zram: support page writeback")
Signed-off-by: Minchan Kim <minchan(a)kernel.org>
Reported-by: Amos Bianchi <amosbianchi(a)google.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky(a)gmail.com>
Cc: John Dias <joaodias(a)google.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
drivers/block/zram/zram_drv.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/block/zram/zram_drv.c~zram-fix-broken-page-writeback
+++ a/drivers/block/zram/zram_drv.c
@@ -638,8 +638,8 @@ static ssize_t writeback_store(struct de
if (strncmp(buf, PAGE_WB_SIG, sizeof(PAGE_WB_SIG) - 1))
return -EINVAL;
- ret = kstrtol(buf + sizeof(PAGE_WB_SIG) - 1, 10, &index);
- if (ret || index >= nr_pages)
+ if (kstrtol(buf + sizeof(PAGE_WB_SIG) - 1, 10, &index) ||
+ index >= nr_pages)
return -EINVAL;
nr_pages = 1;
@@ -663,7 +663,7 @@ static ssize_t writeback_store(struct de
goto release_init_lock;
}
- while (nr_pages--) {
+ for (; nr_pages != 0; index++, nr_pages--) {
struct bio_vec bvec;
bvec.bv_page = page;
_
Patches currently in -mm which might be from minchan(a)kernel.org are
zram-fix-return-value-on-writeback_store.patch
zram-fix-broken-page-writeback.patch
mm-remove-lru_add_drain_all-in-alloc_contig_range.patch
mm-page_alloc-dump-migrate-failed-pages.patch
mm-vmstat-add-cma-statistics.patch
mm-cma-support-sysfs.patch
The patch titled
Subject: zram: fix return value on writeback_store
has been added to the -mm tree. Its filename is
zram-fix-return-value-on-writeback_store.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/zram-fix-return-value-on-writebac…
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/zram-fix-return-value-on-writebac…
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Minchan Kim <minchan(a)kernel.org>
Subject: zram: fix return value on writeback_store
writeback_store's return value is overwritten by submit_bio_wait's return
value. Thus, writeback_store will return zero since there was no IO
error. In the end, write syscall from userspace will see the zero as
return value, which could make the process stall to keep trying the write
until it will succeed.
Link: https://lkml.kernel.org/r/20210312173949.2197662-1-minchan@kernel.org
Fixes: 3b82a051c101("drivers/block/zram/zram_drv.c: fix error return codes not being returned in writeback_store")
Signed-off-by: Minchan Kim <minchan(a)kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky(a)gmail.com>
Cc: Colin Ian King <colin.king(a)canonical.com>
Cc: John Dias <joaodias(a)google.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
drivers/block/zram/zram_drv.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
--- a/drivers/block/zram/zram_drv.c~zram-fix-return-value-on-writeback_store
+++ a/drivers/block/zram/zram_drv.c
@@ -627,7 +627,7 @@ static ssize_t writeback_store(struct de
struct bio_vec bio_vec;
struct page *page;
ssize_t ret = len;
- int mode;
+ int mode, err;
unsigned long blk_idx = 0;
if (sysfs_streq(buf, "idle"))
@@ -728,12 +728,17 @@ static ssize_t writeback_store(struct de
* XXX: A single page IO would be inefficient for write
* but it would be not bad as starter.
*/
- ret = submit_bio_wait(&bio);
- if (ret) {
+ err = submit_bio_wait(&bio);
+ if (err) {
zram_slot_lock(zram, index);
zram_clear_flag(zram, index, ZRAM_UNDER_WB);
zram_clear_flag(zram, index, ZRAM_IDLE);
zram_slot_unlock(zram, index);
+ /*
+ * Return last IO error unless every IO were
+ * not suceeded.
+ */
+ ret = err;
continue;
}
_
Patches currently in -mm which might be from minchan(a)kernel.org are
zram-fix-return-value-on-writeback_store.patch
zram-fix-broken-page-writeback.patch
mm-remove-lru_add_drain_all-in-alloc_contig_range.patch
mm-page_alloc-dump-migrate-failed-pages.patch
mm-vmstat-add-cma-statistics.patch
mm-cma-support-sysfs.patch
cppcheck warning:
sound/soc/samsung/tm2_wm5110.c:605:6: style: Variable 'ret' is
reassigned a value before the old one has been
used. [redundantAssignment]
ret = devm_snd_soc_register_component(dev, &tm2_component,
^
sound/soc/samsung/tm2_wm5110.c:554:7: note: ret is assigned
ret = of_parse_phandle_with_args(dev->of_node, "i2s-controller",
^
sound/soc/samsung/tm2_wm5110.c:605:6: note: ret is overwritten
ret = devm_snd_soc_register_component(dev, &tm2_component,
^
The args is a stack variable, so it could have junk (uninitialized)
therefore args.np could have a non-NULL and random value even though
property was missing. Later could trigger invalid pointer dereference.
There's no need to check for args.np because args.np won't be
initialized on errors.
Fixes: 8d1513cef51a ("ASoC: samsung: Add support for HDMI audio on TM2 board")
Cc: <stable(a)vger.kernel.org>
Suggested-by: Krzysztof Kozlowski <krzk(a)kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski(a)canonical.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki(a)samsung.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart(a)linux.intel.com>
---
sound/soc/samsung/tm2_wm5110.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/soc/samsung/tm2_wm5110.c b/sound/soc/samsung/tm2_wm5110.c
index 9300fef9bf26..125e07f65d2b 100644
--- a/sound/soc/samsung/tm2_wm5110.c
+++ b/sound/soc/samsung/tm2_wm5110.c
@@ -553,7 +553,7 @@ static int tm2_probe(struct platform_device *pdev)
ret = of_parse_phandle_with_args(dev->of_node, "i2s-controller",
cells_name, i, &args);
- if (!args.np) {
+ if (ret) {
dev_err(dev, "i2s-controller property parse error: %d\n", i);
ret = -EINVAL;
goto dai_node_put;
--
2.25.1